This request for core support is based on the desirability of maintaining and improving a research resource in the fundamental aspects of radiation oncology now in existence at this institution. Although all individual research projects presently associated with the Divisions of Radiation Biology and Radiologic Physics have been subject to peer review and are funded by separate grants, they also have a common primary objective - namely, the study of the basic nature of and the detection and treatment of cancer through the use of radiation. A perhaps less important but inseparable objective of the staff associated with these endeavors has been the education and training of individuals specializing in varous aspects of radiation effects and ranging from pre-doctoral graduate students to post-doctoral investigators and residents in radiology. Funding aimed at (1) support of common service type mechanical shops, tissue culture facilities, library, and administration, etc., (2) salary support for staff investigators, and (3) modest but critical developmental research support should materially improve the efficacy of the personnel and eventually increase research contributions in radiation oncology.